CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 16,389	$ 16,487
Accounts receivable, net of allowance for doubtful accounts of $134 and $141, respectively	3,575	3,393
Inventories	3,121	2,794
Prepaid expenses and other current assets	430	536
Total current assets	23,515	23,210
Property and equipment, net	4,962	5,301
Operating lease right-of-use assets, net	755	0
Intangible assets, net	9,312	9,765
Goodwill	8,803	8,803
Other assets	392	428
Total assets	47,739	47,507
Current liabilities:
Current portion of long-term debt	1,010	252
Accounts payable	2,045	1,764
Other accrued liabilities	4,724	4,500
Current portion of operating lease liabilities	293	0
Deferred revenues	2,063	2,099
Total current liabilities	10,135	8,615
Long-term liabilities:
Long-term debt, net	6,421	7,145
Deferred tax liability	69	111
Long-term operating lease liabilities, net	479	0
Other liabilities	397	388
Total liabilities	17,501	16,259
Commitments and contingencies (see Note 15)
Stockholders' equity:
Common Stock, $.001 par value, 150,000,000 shares authorized; 31,120,608 and 29,943,086 shares issued and outstanding at March 31, 2019 and December 31, 2018, respectively	31	30
Additional paid-in capital	242,310	241,988
Accumulated deficit	(212,104)	(210,771)
Total stockholders' equity	30,238	31,248
Total liabilities and stockholders' equity	47,739	47,507
Series C Convertible Preferred Stock [Member]
Stockholders' equity:
Series C Convertible Preferred Stock, $.10 par value, 10,000,000 shares authorized; 6,878 and 9,968 shares issued and outstanding at March 31, 2019 and December 31, 2018, respectively	$ 1	$ 1